Vitamin E is the name given to a group of eight compounds called tocopherols that were discovered in the 1920s. Alpha tocopherol is the most potent and most commonly used form of this fat-soluble nutrient. Vitamin E functions as a powerful antioxidant to protect human cells and fatty tissues from free radical damage. Free radicals are extremely dangerous and reactive oxygen compounds that are constantly being produced from a variety of natural sources such as radiation, air pollution, and the breakdown of proteins in the body. Left unchecked, free radicals course throughout the body, rupturing cell membranes, causing massive damage to skin and connective tissues, and damage cellular DNA which gives rise to various cancers and degenerative diseases. Free radical damage also accumulates in the brain, leading to age-related memory impairment.

Vitamin E, in combination with other antioxidants, works to quench free radicals and prevent oxidation of polyunsaturated fatty acids that make up cell membranes. By neutralizing free radicals and stabilizing fatty cell membranes, vitamin E helps to prevent cancer, arthritis, immune disorders such as lupus, and premature aging. Working with vitamin A and beta carotene, vitamin E protects the lungs from air pollution. Vitamin E also protects the cells lining blood vessels walls from free radical damage, thus preventing atherosclerosis and cardiovascular disease. By protecting red blood cells from damage, vitamin E also prevents a special form of anemia called hemolytic anemia.

Vitamin E also plays an important role in the production of prostaglandins, vital hormone-like substances that regulate blood pressure, reproduction, and muscle contractions. By acting as a antithrombin agent vitamin E can help prevent heart attacks by controlling the formation of potentially fatal blood clots. Vitamin E is also used in the treatment of fibrocystic breasts and premenstrual syndrome, promotes healing while reducing scarring, and prevents the formation of cataracts in the eyes. Recently, researchers reported that men taking vitamin E supplements experience 34% few cases of prostate cancer, and 16% fewer cases of colorectal cancer.

A deficiency of Vitamin E can cause hemolytic anemia in infants, wherein red blood cells are destroyed. Adults rarely experience symptoms of vitamin E deficiency unless afflicted with fat malabsorption syndromes such as cystic fibrosis, sprue and celiac disease. Symptoms are easily treated with alleviated with vitamin E supplementation.

The male sex gland, the testis, is responsible for the production of sperm and the secretion of testosterone. Testosterone, the hormone responsible for sexual desire, is dependent on vitamin E to produce sperm and to provide strong masculine features. The female sex glands, the ovaries, produce estrogen and progesterone. For these hormones to function properly, they require adequate amounts of both vitamin E and niacin.